Synthesis and characterization of novel magnetic polyurethane nanocomposites based on 1,5-Naphthalene diisocyanate (NDI) containing Clay-Fe3O4@APTS nanoparticles

In the present work, we reported on the preparation of novel magnetic clay-Fe3O4@APTS nanoparticle by sol-gel process with the aim to use it in the synthesis of magnetic polyurethane nanocomposite and study of their magnetic, thermal and mechanical behavior. Magnetic nanoparticles (MNPs) were prepared by intercalation of Fe3O4 nanoparticles into the nanoclay layers and further surface modification by aminopropyltriethoxysilane (APTS). The synthesized Clay-Fe3O4@APTS nanoparticles were characterized by FT-IR, TGA and SEM. Magnetic polyurethane nanocomposites were successfully synthesized by incorporation of Clay-Fe3O4@APTS nanoparticles in the polypropylene glycol (PPG) and 1,5-Naphthalene diisocyanate (NDI) based polyurethane matrix using in situ polymerization method. polypropylene glycol constitute the soft segment whereas 1,5-Naphthalene diisocyanate (NDI) with the high melting point and the rigid and aromatic naphthalene structure form the hard segments with superior physical strength and thermal stability which are extended by 1,4-butanediol (BDO). The prepared nanocomposites were identified by FT-IR. The morphology, magnetic and mechanical features of magnetic polyurethane nanocomposites were evaluated by XRD, AFM, MFM, TGA, DMTA and VSM, respectively. AFM and MFM analysis showed good dispersion of Clay-Fe3O4@APTS nanoparticles within the polyurethane matrices even at 3.5 pbw (parts by weight), which attributed to the formation of covalent bonding between functionalized MNPs and polymer chains. It was demonstrated that incorporation of magnetic nanoparticles enhanced the thermal stability of polyurethane nanocomposite, especially, for the PU 3.5 wt% nanocomposite compared to pure PU.